A variety of flavorants have been developed and proposed for incorporation into tobacco products. Illustrative of such tobacco flavorants are those described in U.S. Pat. Nos. 3,580,259; 3,625,224; 3,722,516; 3,750,674; 3,879,425; 3,881,025; 3,884,247; 3,890,981; 3,903,900; 3,914,451; 3,915,175; 3,920,027; 3,924,644; 3,937,228; 3,943,943; 3,586,387; 3,379,754; and the like.
J. C. Leffingwell et al "Tobacco Flavoring For Smoking Products" (R.J. Reynolds publication, 1972) recites a listing of desirable flavorants for smoking compositions, which include phenols, terpenols and lactones such as guaiacol, 1-undecanol and 5-dodecalactone.
The high degree of volatility and ease of sublimation of flavorant additives in tobacco products have presented problems in the manufacturing operations, and have resulted in a decreased shelf-life of the products due to losses of flavorant by evaporation on storage.
Recent developments have involved incorporating a low volatility organic additive in a smoking composition, which under smoking conditions is pyrolyzed into one or more fragments that function to improve the taste and character of mainstream tobacco smoke, and in some cases a consequential improvement of sidestream smoke aroma.
U.S. Pat. No. 3,312,226 describes smoking tobacco compositions which contain an ester additive such as l-menthyl linalool carbonate. Under smoking conditions pyrolysis of the carbonate ester releases menthol which flavors the mainstream smoke.
U.S. Pat. Nos. 4,119,106; 4,171,702; 4,177,339; and 4,212,310 describe oligomeric and polymeric carbonates ester derivatives which as constituents of smoking compositions are stable and non-volatile under storage conditions, and are adapted to release pyrolysis products under smoking conditions that improve the taste and aroma of the smoke.
Of particular interest with respect to the present invention are U.S. Pat. Nos. 3,332,428 and 3,419,543 that describe smoking tobacco compositions which contain a menthyl carbonate ester of a glycol and saccharide, which under smoking conditions decomposes to release free menthol into the mainstream smoke. U.S. Pat. No. 3,499,452 discloses similar smoking tobacco compositions in which a carbonate ester additive releases flavorant volatiles other than menthol.
There is continuing research effort to develop low delivery smoking compositions which generate mainstream smoke with enhanced taste and character under smoking conditions.
Accordingly, it is an object of this invention to provide smoking compositions having incorporated therein a flavorant-release component which is characterized by lack of mobility and/or volatility at ambient temperature.
It is another object of this invention to provide smoking tobacco compositions having incorporated therein a menthol-release additive which under normal smoking conditions imparts improved flavor to mainstream smoke and improved aroma to sidestream smoke.
It is a further object of this invention to provide a novel menthyloxycarbonlglucose mixture, and an improved process for producing the mixture.
Other objects and advantages of the present invention shall become apparent from the following description and examples.